Field of the Invention:
The invention relates to a storage device for stackable containers for conveying items, in particular items of luggage, in a sorting conveyor system in an airport.
Items of luggage deposited at departure desks of an airport are conveyed by means of a sorting conveyor system to sorting end points, at which vehicles are loaded with items of luggage for specific aircraft. As a rule in such cases the items of luggage generally cover quite large distance on an automated conveyor system between check-in point and sorting end point. In large sorting conveyor systems the items of luggage are transported individually on a tray-shaped container in each case. At the sorting end points the items of luggage are separated from the containers, which are then taken back and may have to be stored before being loaded with new items of luggage. Now the demand for containers in the sorting conveyor system is often different, high in the morning and the evening for example, while being low at midday and during the night. The problem arising as a result of these peak loads of an airport is that, when demand is low, a large number of empty containers are transported unused in the sorting conveyor system, or with short-term high demand there are not sufficient empty containers available for loading, since these are in transit in the sorting conveyor system.
A device for stacking and unstacking containers is known from publication DE 34 16 928 A1. The device consists of a stand which bears a pair of cantilever arms for each stack so that the container-specific carrying elements clamped onto them and therefore rapidly exchangeable carry the lowest container of the stack at its upper edge. Attached below the stacks is a transverse conveyor, generally embodied as a chain roller conveyor, which connects all stacks to one another and which simultaneously serves as a lifting frame for simultaneously operating all stacks. The lifting frame is guided with known guide devices in the stand and is raised and lowered with likewise known spindle drives. The operation of the stack from below makes a small height of the device possible as well as enabling material to flow through below the stacks.
The translation DE 699 17 028 T2 of the European Patent document EP 1 091 895 B1 discloses a transport system for transporting items such as for example luggage at an airport, in which a congestion device for storing and pre-sorting at least a part of the flow of items through the system is provided. Each item has a storage device, which conveys at least one object. The transport system has a first conveyor for transporting items from the loading station to an item storage arrangement and a second conveyor for transporting items from the item storage arrangement to the unloading station. The item storage arrangement has a number of storage units. Each storage unit has a storage section defined by a frame rack of a storage frame, which is inclined in the direction of its front end and has steel rollers on which the storage devices can slide. Each storage unit further has a loading unit for loading storage devices into the storage section and unloading storage devices from the storage section and for moving storage devices along the front end of a horizontal plane of the storage section. Between the horizontal planes the storage devices are moved by two lifts, wherein one lift for loading storage containers is arranged on one side of the frame rack and the other lift for unloading storage containers from the frame rack is arranged on its opposite side. The lifts are essentially placed in the same vertical plane as the loading units.
The disadvantage of the known devices is that they operate slowly and they are expensive.